Grass drops a ton of seeds, including a ton of different advanced seeds. I would suggest that it should be more in line with vanilla - dropping wheat, rye, barley, and the like, but requiring the rest be gotten from zombie drops, villages, chests, and other sources of the vanilla advanced seeds.

I would be in favor of removing seed drops from grass entirely by default. Getting them from villages or wild crops is more interesting.

In vanilla, finding sugarcane or getting a potato from a zombie is a notable achievement. Pam's Harvestcraft encourages exploration by dropping different seeds in different climates. I would like to see more of that.

Mmm, my thought exactly. Perhaps the seeds could drop from grass, but only in particular biomes? Not sure how easy that is to implement.

Found a great mod for you. It is regularly updated and not only works with one mod, but any mod you have that adds seeds. This is going to be better than anything a single mod author would do to change their loot tables because except if you wanted to change the ratio of drops from different seeds within a single mod, which is not what you are asking.

https://www.curseforge.com/minecraft/mc-mods/seed-drop-control

It's not just the number of seeds - it would make finding seeds much more interesting. Vanilla does this pretty well, with wheat seeds dropping from grass, and with melons and pumpkins spawning in some biomes, and then carrots, potatoes, and beetroot being zombie and villager drops. Or Farmer's Delight adds wild plants one can get seeds from, and those also work pretty well. Pam's Harvestcraft had the various garden plants one could find in particular biomes, and that also made finding plants a bit of an adventure.